1. Field of the Invention:
The present invention relates to electrical sensors of the type useful for controlling electrical flow through a circuit. The present invention specifically involves the use of a tactile feedback dome-cap in conjunction with pressure-sensitive variable-conductance material to provide momentary-On pressure dependant variable electrical output. The tactile feedback is user discenable for indicating actuation and de-actuation of the sensor. Novel structural embodiments and methods of manufacturing are disclosed.
2. Description of the Related Prior Art
There are many prior art types of switches (sensors) and switch packages. While used widely in many fields, switches and switch packages are used in game controllers for use in controlling imagery, and in computer keyboards, other computer peripherals, and in many other host devices not related to computers.
A very common prior art switch is comprised of: a housing typically of non-conductive plastics; a first and a second conductive element fixed to the housing and in-part within the housing and in-part exposed external of the housing; a conductive dome-cap typically made of metal having a degree of resiliency and positioned within a recess of the housing and between a depressive actuator and the two conductive elements. The actuator is retained to the housing via a flange of the actuator positioned beneath a housing plate with a portion of the actuator extending through a whole in the housing plate to be exposed external of the housing and thus accessible for depression by a mechanical member or a human finger or thumb. Typically, at the four comers of the housing are plastic studs formed of continuations of the housing material.
The distal ends of the studs pass through aligned holes in the housing plate, and when the housing plate is properly located, the distal ends of the studs are flattened and enlarged commonly using heating and mechanical pressure so as to retain the housing plate to the housing.
The conductive elements are typically highly conductive and serve as electrical conductors but also sometimes additionally serve as mechanical members or legs for structural attachment to circuit boards, although they are of ten connected directly to wires. The two conductive elements are separated from one another within the housing in a normally open arrangement or fashion. An end portion of the first conductive element within the housing is positioned to be in constant contact with an edge of the dome-cap. Sufficient depression of the actuator causes the actuator to apply force to the dome-cap, causing the dome-cap to bow (snap-through) downward, causing a center portion of the dome-cap to contact a more centrally positioned end of the second conductive element and resulting in a conductive bridging or closing between the first and second conductive elements with the current flow path being through the conductive dome-cap. The dome-cap when pressed against sufficiently to bow toward the second conductive element has resistance to moving which begins low and increases toward a snap-through threshold wherein at the threshold the dome-cap snaps creating a snap or click which is user discenable in the form of a tactile sensation. The dome-cap then moves further toward the second conductive element. The dome-cap being of resilient design, returns to a raised position off of the second conductive element when the actuator is no longer depressed, and thus the switch or sensor is a momentary-On type. A tactile sensation is also produced by the dome-cap upon returning to the normally raised position and in doing so moving back through the snap-through threshold. As those skilled in the art recognize, the portion of the actuator which is external of the housing can be of numerous sizes and shapes, for example to accommodate attachment of extending and/or enclosing members such as buttons and the like, etc.
Such prior art switches are either On or Off and provide corresponding all or nothing outputs. These simple On/Off switches are not structured to provide the user proportional or analog control which is highly desirable and would be very beneficial in many applications.
Another type of prior art sensor is described in U.S. Pat. No. 3,806,471 issued Apr. 23, 1974 to R. J. Mitchell for xe2x80x9cPRESSURE RESPONSIVE RESISTIVE MATERIALxe2x80x9d. Mitchell describes sensors which utilize pressure-sensitive variable-conductance material to produce analog outputs. However, Mitchell fails to recognize any need for tactile feedback to the user upon actuation and de-actuation of the sensor. Thus, Mitchell fails to anticipate any structuring useful for providing a tactile feedback discenable to a human user of his sensors.
There have been hundreds of millions of momentary-On snap switches made and sold in the last 25 years. Pressure-sensitive variable-conductance sensors have also been known for decades, and yet the prior art does not teach a pressure-sensitive variable-conductance sensor which includes tactile feedback to the user upon actuation and de-actuation of the sensor. Clearly a pressure-sensitive variable-conductance sensor which included tactile feedback to the user would be of significant usefulness and benefit, particularly if provided in a structural arrangement which was inexpensive to manufacture. Such a sensor would be useful in a wide variety of applications wherein human input is required. Such applications would include home electronics, computers and generally devices operated by the human hand/finger inputs.
The following summary and detailed description is of preferred structures and best modes for carrying out the invention, and although there are clearly variations which could be made to that which is specifically herein described and shown in the included drawings, for the sake of brevity of this disclosure, all of these variations and changes which fall within the true scope of the present invention have not been herein detailed, but will become apparent to those skilled in the art upon a reading of this disclosure.
The present invention involves the use of pressure-sensitive variable-conductance material electrically positioned as a variably conductive element between highly conductive elements in a structural arrangement capable of providing variable electrical output coupled with structuring for providing tactile feedback upon depression of an depressive actuator, and preferably tactile feedback with termination of the depression of the actuator. The tactile feedback is preferably discernible for both actuation and de-actuation of the sensor, the actuation and de-actuation of the sensor controllable by way of depression and release of the depressive actuator.
The present invention provides a pressure-sensitive variable electrical output sensor which produces a tactile sensation discenable to the human user to alert the user of the sensor being activated and deactivated.
A sensor in accordance with the present invention provides the user increased control options of host devices, the ability to variably increase and reduce the sensor output dependant on pressure exerted by the user to a depressive actuator so that, for example, images may selectively move faster or slower on a display, timers, settings, adjustments and the like may change faster or slower dependant on the pressure applied by the user. A benefit provided by a sensor in accordance with the present invention is a reduction of confusion or potential confusion on the part of the user as to when the analog sensor is actuated and de-actuated. If an analog sensor of the type not having tactile feedback is minimally activated, it is difficult for the user in some instances to determine whether the sensor is still minimally activated or is entirely de-activated. For example, if the user is playing an electronic game utilizing a variable pressure analog sensor to control a fire rate of a gun, and desires the gun to be firing very slowly, i.e., one shot every 5 seconds or so, the user would-be depressing very lightly on the sensor, and would not be immediately aware when he inadvertently decreased the depression enough to fully deactivate the sensor. Conversely for example, without tactile feedback in the same arrangement, the user of the electronic game may desire that gun should begin to fire very slowly such as to conserve ammo, and by lightly depressing on the sensor the fire rate would be slow, however the user does not immediately receive any notice even upon minimal activation of the sensor and thus might initially depress so firmly as to cause a firing volley and expend excessive ammo. The present invention solves the above and like problems.
Another example of reduced confusion of the user would be brought about through the use of the present invention in devices having a single operable member operable through a plurality of axes with each axis associated with one or two sensors. Such device which would be benefited by the application of the present invention would be my SIX DEGREE OF FREEDOM CONTROLLER of U.S. Pat. No. 5,565,891.
Still another benefit of the present sensor is that the preferred structure is inexpensive to manufacture, costing essentially the same or just slightly more than prior art momentary-On tactile switches of the type manufactured in large volume and highly automated manufacturing facilities.
Further, a sensor in accordance with a preferred embodiment of the present invention is structured to allow manufacturing of the sensor absent major and costly tooling and assembly line changes to existing large volume, highly automated manufacturing facilities.
Additionally, a sensor in accordance with a preferred embodiment of the present invention is structured in a familiar format having a housing and electrical connectors similar to high-volume prior art momentary-On switches so that designers may easily substitute the present invention sensors directly for the prior art devices and receive the corresponding benefits of the new improved sensors. For example, where prior art momentary-On switches are utilized as sensors located within a joys tick handle for buttons located on the handle operable by the user""s fingers (or thumbs), the present sensor can be substituted for the prior art switches without re-tooling the mounting structure within the joys tick handle and without retraining of workers who install the sensors.
A yet still further benefit of a sensor in accordance with a preferred embodiment of the present invention is that the sensor is an integrally packaged unit, i.e., manufactured in a complete packaged unit containing pressure-sensitive variable-conductance material, two proximal highly conductive elements, a depressive actuator, a resilient dome-cap for providing tactile feedback, and all integrated together with a housing,there by providing ease of handling and installation, among other benefits.
These, as well as other benefits and advantages of the present invention will be increasingly appreciated and understood with continued reading and with a review of the included drawings.